Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1592329
| From | Dave Chinner <david@fromorbit.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail |
| Date | 2017-03-04 00:00 +0100 |
| Message-ID | <th4l3-7SF-1@gated-at.bofh.it> (permalink) |
| References | <tgAZH-4mT-1@gated-at.bofh.it> <tgB9n-4qi-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, Mar 02, 2017 at 04:45:40PM +0100, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> Even though kmem_zalloc_greedy is documented it might fail the current
> code doesn't really implement this properly and loops on the smallest
> allowed size for ever. This is a problem because vzalloc might fail
> permanently - we might run out of vmalloc space or since 5d17a73a2ebe
> ("vmalloc: back off when the current task is killed") when the current
> task is killed. The later one makes the failure scenario much more
> probable than it used to be because it makes vmalloc() failures
> permanent for tasks with fatal signals pending.. Fix this by bailing out
> if the minimum size request failed.
>
> This has been noticed by a hung generic/269 xfstest by Xiong Zhou.
>
> fsstress: vmalloc: allocation failure, allocated 12288 of 20480 bytes, mode:0x14080c2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO), nodemask=(null)
> fsstress cpuset=/ mems_allowed=0-1
> CPU: 1 PID: 23460 Comm: fsstress Not tainted 4.10.0-master-45554b2+ #21
> Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 10/05/2016
> Call Trace:
> dump_stack+0x63/0x87
> warn_alloc+0x114/0x1c0
> ? alloc_pages_current+0x88/0x120
> __vmalloc_node_range+0x250/0x2a0
> ? kmem_zalloc_greedy+0x2b/0x40 [xfs]
> ? free_hot_cold_page+0x21f/0x280
> vzalloc+0x54/0x60
> ? kmem_zalloc_greedy+0x2b/0x40 [xfs]
> kmem_zalloc_greedy+0x2b/0x40 [xfs]
> xfs_bulkstat+0x11b/0x730 [xfs]
> ? xfs_bulkstat_one_int+0x340/0x340 [xfs]
> ? selinux_capable+0x20/0x30
> ? security_capable+0x48/0x60
> xfs_ioc_bulkstat+0xe4/0x190 [xfs]
> xfs_file_ioctl+0x9dd/0xad0 [xfs]
> ? do_filp_open+0xa5/0x100
> do_vfs_ioctl+0xa7/0x5e0
> SyS_ioctl+0x79/0x90
> do_syscall_64+0x67/0x180
> entry_SYSCALL64_slow_path+0x25/0x25
>
> fsstress keeps looping inside kmem_zalloc_greedy without any way out
> because vmalloc keeps failing due to fatal_signal_pending.
>
> Reported-by: Xiong Zhou <xzhou@redhat.com>
> Analyzed-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Signed-off-by: Michal Hocko <mhocko@suse.com>
> ---
> fs/xfs/kmem.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
> index 339c696bbc01..ee95f5c6db45 100644
> --- a/fs/xfs/kmem.c
> +++ b/fs/xfs/kmem.c
> @@ -34,6 +34,8 @@ kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)
> size_t kmsize = maxsize;
>
> while (!(ptr = vzalloc(kmsize))) {
> + if (kmsize == minsize)
> + break;
> if ((kmsize >>= 1) <= minsize)
> kmsize = minsize;
> }
Seems wrong to me - this function used to have lots of callers and
over time we've slowly removed them or replaced them with something
else. I'd suggest removing it completely, replacing the call sites
with kmem_zalloc_large().
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Christoph Hellwig <hch@infradead.org> - 2017-03-02 01:40 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Xiong Zhou <xzhou@redhat.com> - 2017-03-02 06:40 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2017-03-02 07:50 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 09:50 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Xiong Zhou <xzhou@redhat.com> - 2017-03-02 10:30 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Bob Liu <liubo95@huawei.com> - 2017-03-02 07:50 +0100
Re: mm allocation failure and hang when running xfstests generic/269on xfs Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-03-02 12:50 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-03-02 13:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 13:30 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 13:30 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 14:10 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 15:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 15:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 16:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 16:40 +0100
[PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Michal Hocko <mhocko@kernel.org> - 2017-03-02 16:50 +0100
[PATCH 2/2] xfs: back off from kmem_zalloc_greedy if the task is killed Michal Hocko <mhocko@kernel.org> - 2017-03-02 16:50 +0100
Re: [PATCH 2/2] xfs: back off from kmem_zalloc_greedy if the task is killed Christoph Hellwig <hch@lst.de> - 2017-03-02 17:00 +0100
Re: [PATCH 2/2] xfs: back off from kmem_zalloc_greedy if the task is killed Brian Foster <bfoster@redhat.com> - 2017-03-02 17:10 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Brian Foster <bfoster@redhat.com> - 2017-03-02 17:10 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Christoph Hellwig <hch@lst.de> - 2017-03-02 17:20 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Michal Hocko <mhocko@kernel.org> - 2017-03-02 17:40 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-03-02 17:50 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Dave Chinner <david@fromorbit.com> - 2017-03-04 00:00 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-03-04 00:30 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Dave Chinner <david@fromorbit.com> - 2017-03-04 05:50 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Michal Hocko <mhocko@kernel.org> - 2017-03-06 14:30 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 20:20 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Christoph Hellwig <hch@infradead.org> - 2017-03-02 19:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 20:20 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 16:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 18:40 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 15:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 15:10 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-03-02 17:00 +0100
csiph-web